Windows will only boot w/ only SSD not SSD + HDD

[7Sav]

I have tried windows 10 and Windows 7 and they both are having an issue with this problem in which windows perfectly boots up and loads everything if I only have the SSD plugged in, however if i also plug in my HDD then it just sits in the boot up loading screen for forever. The SSD is in first priority w ACHI and I have tried different SATA cables and ports..

I7 4790k
MSI R9 390
GSKill RipJawZ 8GB
MSI Z97 Gaming 5
Kingston V300 120 GB SSD
WD Blue 1 TB HDD
EVGA NEX750G 750 W 80+ Gold PSU

 

[ktolo]

You had an OS installed on the HDD before you got your SSD?
It sounds like there is an MBR on both the SSD and on the HDD - and this is causing the system to hang at startup.
Both disks could be marked as Active?
Using a Windows startup disk (install disk) Boot to 'fix my computer' - and use diskpart to determine if this is the case.
Then just remove the 'active' mark from the HDD.
Just google 'marking a disk active in diskpart' and 'booting to command prompt / windows startup options'

Another, albeit much more time consuming solution would be to backup your HDD, copy it's contents to an external HDD or something, format it and copy the stuff back onto it..

 

[Boogieman_WD]

Hey there, 7Sav.

I'm really sorry to hear about the issues you're having with your drive. Have you had any problems prior to this happening? Any unusual sounds/noises coming from it, slow read/write speed, system freezing/hanging when you try to access it, etc? Do you have data you need to recover from that HDD?
I'd suggest that you try the drive with a different computer as well, to see if the same thing happens, or at least try it externally with yours via a SATA to USB adapter, external enclosure, or a docking station, to see if the drive can be detected. If it's recognized and if you don't need to recover data, I'd suggest that you download DLG (Data Lifeguard Diagnostics) and run both tests (Quick and Extended), to see if anything unusual pops-up. Here's how to do that: How to test a drive for problems using Data Lifeguard Diagnostics for Windows.
Also if the drive is properly recognized without any issues with a different computer, I'd suggest that you try resetting/updating your BIOS/UEFI, to see if that fixes things up.
Also there could be some conflicts if you've had previously installed the same OS on the HDD.

edit: Oops, seems like you've already received the right answer while I was typing

Hope that helps. Please let me know how everything goes.
Boogieman_WD